6.5 TCU again

[longgun]

I finally got a chance to set up my chronograpy and do some shooting with my 6.5 tcu.   The rig produces good results with 140 gr Amax bullets and 26.0 gr of N 140 for short line critters.   But the Ram loads are rather a disappointment.  The fireformed cases will hold 29.0 gr of N 150 but they tend to come apart with this much powder.  Primers do show pressure signs but not really excessive.  The problem is that the rim of the brass swells about .005" just enough so that the brass will not go back into the shell holder for resizing.  And this load only produces about 2475 f/s.   28.5 gr of n 150 shows no problems with the brass, however this velocity is only 2450 f/s.  My experience tells me that I need 2550 f/s to take rams marginally.   2650 f/s for reliable ram knock down.  I was using winchester  and federal brass and saw no advantage of one over the other.

For fun  I loaded some 107 Sierra Match Kings  with 27.7 gr of N 133 with results of 2800 f/s and decent accuracy.   Got the same results with N 130 and good accuracy.   Is 2800 f/s enough velocity to take the rams with 107's?   Seems like there were some folks using 107 SMK on the rams at Raton couple of years ago.  Think what I really need is a 125 g VLD bullet.

My chamber is machined for 140 gr Amax bullets. Perhaps I ought to consider re-doing the chamber for shorter bullets and get the velocity up a tad.  Recoil with the 107 smk was a real hoot..........

[tirador]

Hello longgun, you may want to try the LAPUA 123 gr. I have been using them in both a 6.5 BR improved and my 260 hunting class rifle with excellent results.
I have not tried to knock down any rams though; I am only using them in the first three distances.
There is a fellow in San Francisco named Bob Cauterusio (sp) that makes great 6.5 bullets using 7mm jackets, a lot of the Washington shooters use them for rams. I bought a bunch of 151's and as far as I am concerned they are the best for knocking down rams with 42 gr of Hodgon or IMR 4350 in a 260. I believe he makes some bullets that are lighter but I forgot how many different weights he offers in the 6.5 cal. I hope this helps you. Tony

[K2]

You may have hit what is known as diminishing returns where a huge amount of effort is required to get a very small gain in performance.   In agriculture yeilds increased dramatically from teh 1700's to the 1900's. If one were to extrapolate those gains he could conclude that we could grow the worlds food supply in a flower pot, but then reality sets in  :wink:  Unless there is some fantastic discovery in powder development I think you are hitting the limits of the TCU case capacity.  In your quest be careful not to hurt yourself or others with a blowup.  

I finally got a chance to set up my chronograpy and do some shooting with my 6.5 tcu.   The rig produces good results with 140 gr Amax bullets and 26.0 gr of N 140 for short line critters.   But the Ram loads are rather a disappointment.  The fireformed cases will hold 29.0 gr of N 150 but they tend to come apart with this much powder.  Primers do show pressure signs but not really excessive.  The problem is that the rim of the brass swells about .005" just enough so that the brass will not go back into the shell holder for resizing.  And this load only produces about 2475 f/s.   28.5 gr of n 150 shows no problems with the brass, however this velocity is only 2450 f/s.  My experience tells me that I need 2550 f/s to take rams marginally.   2650 f/s for reliable ram knock down.  I was using winchester  and federal brass and saw no advantage of one over the other.

For fun  I loaded some 107 Sierra Match Kings  with 27.7 gr of N 133 with results of 2800 f/s and decent accuracy.   Got the same results with N 130 and good accuracy.   Is 2800 f/s enough velocity to take the rams with 107's?   Seems like there were some folks using 107 SMK on the rams at Raton couple of years ago.  Think what I really need is a 125 g VLD bullet.

My chamber is machined for 140 gr Amax bullets. Perhaps I ought to consider re-doing the chamber for shorter bullets and get the velocity up a tad.  Recoil with the 107 smk was a real hoot..........

[jimann]

Hi
I shoot a 6.5 IHMSA and had a problem with the rams...I found some Lapua 144 full metal jacket match bullets. They hang together long enough the rams will go over, and I don't load them hot. These bullets might work for your 6.5 TCU.
Good luck
jim

[DanDeMan]

Don,

Use military brass for your ram loads.  Commercial brass is too soft and weak in the web area of the case for that much pressure.  I'm shooting 29.0 grains of N150 with no pressure problems using military brass.  The 140's will knock the rams down better than the 123 Lapua bullets.

[DanDeMan]

Don,

I should have added to the previous post that the Lapua 223 brass will also take the ram load pressure.